Here is a small example on how to use Prometheus to scrape your GCE instance.

I recommend you to look at prometheus documentation to see how you can pass the crendentials to your prometheus instance.

scrape_configs:
  - job_name: node_gce
    gce_sd_configs:
      - zone: europe-west1-b
        project: myproject
      - zone: europe-west1-d
        project: myproject
      - zone: europe-west1-c
        project: myproject
    relabel_configs:
      - source_labels: [__meta_gce_public_ip]
        target_label: __address__
        replacement: "${1}:9090"
      - source_labels: [__meta_gce_zone]
        regex: ".+/([^/]+)"
        target_label: zone
      - source_labels: [__meta_gce_project]
        target_label: project
      - source_labels: [__meta_gce_instance_name]
        target_label: instance
      - regex: "__meta_gce_metadata_(.+)"
        action: labelmap

Let’s analyze it.

Zones and projects

    gce_sd_configs:
      - zone: europe-west1-b
        project: project1
      - zone: europe-west1-d
        project: project1
      - zone: europe-west1-c
        project: project2

We have a job named node_gce, which has 3 gce_sd_config objects. One object is attached to one zone and one project.

Relabeling

Setting the address

This example will substitute the private ip by the public ip of your node, and use the port 9090. __address__ is a hidden used by prometheus to get the address to scrape.

      - source_labels: [__meta_gce_public_ip]
        target_label: __address__
        replacement: "${1}:9090"

Zones and project

Now, let’s get automatically a zone label, which will match the gce zone:

      - source_labels: [__meta_gce_zone]
        regex: ".+/([^/]+)"
        target_label: zone

Let’s get a project label, too:

      - source_labels: [__meta_gce_project]
        target_label: project

Instance name

And a human readable instance name, that will match gce instance name:

      - source_labels: [__meta_gce_instance_name]
        target_label: instance

Metadata

The last part of the config will make every metadata of the instance a label in prometheus:

      - regex: "__meta_gce_metadata_(.+)"
        action: labelmap